<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			var arr1 = new Array();
			console.log(arr1.length)

			arr1[0] = "张三";
			arr1[1] = 1;
			arr1[2] = "王五"
			console.log(arr1)
			console.log(arr1.length)

			var arr2 = new Array(3);
			console.log(arr2[0])

			var arr3 = new Array(10, 20, 30, 40, 50)
			console.log(arr3[0])

			var arr4 = [10, 20, 30, 40]
			console.log(arr4)

			var arr5 = [
				[1, 2, 3],
				[4, 5, 6],
				[7, 8, 9],
			];
			var stus = [{
					id: 1,
					name: "张三",
					age: 18
				},
				{
					id: 2,
					name: "李四",
					age: 19
				},
				{
					id: 3,
					name: "王五",
					age: 20
				},
			]
			console.log(stus)
		</script>
	</body>
</html>